Here are the top candidates:
An exact replacement
http://www.boots.com/en/17-Liquid-Eye-Liner_927276/
It's cheap and I know it works, but maybe I should be more adventurous...
Collection 2000 felt tip liner
http://www.boots.com/en/Collection2000-Extreme-24hfelt-tip-liner_1160659/ (the picture's wrong for some reason - don't know why, I did look on the superdrug site but they didn't have it at all)
Some other liner - I have hours to kill in town on Saturday so will probably spend forever browsing both superdrug and boots. Suggestions very welcome :)
